Design of a Broadband Measurement Systerm of Die-lectric Constant Based on Parallel Plate Waveguide

This paper presents a new method of measuring the complex permittivity of solid materials based on a parallel plate waveguide. Based on the analysis and improvement of the parallel plate system model, the testing system is fabricated and verified. The system is used to test the transmission and reflection coeffi-cients of a solid dielectric substrate in the 4–8 GHz frequency band. The normalized scattering parameters are obtained by time do-main gate calibration, and then the complex permittivity is de-duced by the traditional NRW (Nicolson-Ross- Weir) algorithm. Finally, the comparison between theoretical and simulation S pa-rameters of a solid dielectric material at 4–8 GHz is given. Com-pared with the traditional waveguide testing system, the system has the advantages of simple structure, low profile, fast and low cost.